Ultrasonic contrast enhancement of tissue by encapsulated microbubbles.

Pilot studies have shown that gelatin encapsulated microbubbles (GEM) are readily demonstrable ultrasonic contrast agents. GEM injected into hepatic and renal blood vessels resulted in increased echogenicity of the parenchyma in normal rabbits. VS carcinoma implanted in the rabbit liver and kidney showed significantly different echogenicity from that of normal parenchyma following GEM injection. Echogenic bubbles were delivered to different regions by varying the size of GEM.